[PATCH iproute2-next] tc/skbmod: Introduce SKBMOD_F_ECN option

@@ -17,6 +17,7 @@
 #define SKBMOD_F_SMAC	0x2
 #define SKBMOD_F_ETYPE	0x4
 #define SKBMOD_F_SWAPMAC 0x8
+#define SKBMOD_F_ECN	0x10
 
 struct tc_skbmod {
 	tc_gen;

@@ -8,7 +8,8 @@ skbmod - user-friendly packet editor action
 .BR tc " ... " "action skbmod " "{ " "set "
 .IR SETTABLE " | "
 .BI swap " SWAPPABLE"
-.RI " } [ " CONTROL " ] [ "
+.RB " | " ecn
+.RI "} [ " CONTROL " ] [ "
 .BI index " INDEX "
 ]
 

@@ -37,6 +38,12 @@ action. Instead of having to manually edit 8-, 16-, or 32-bit chunks of an
 ethernet header,
 .B skbmod
 allows complete substitution of supported elements.
+Action must be one of
+.BR set ", " swap " and " ecn "."
+.BR set " and " swap
+only affect Ethernet packets, while
+.B ecn
+only affects IP packets.
 .SH OPTIONS
 .TP
 .BI dmac " DMAC"

@@ -51,6 +58,10 @@ Change the ethertype to the specified value.
 .BI mac
 Used to swap mac addresses.
 .TP
+.B ecn
+Used to mark ECN Capable Transport (ECT) IP packets as Congestion Encountered (CE).
+Does not affect Non ECN-Capable Transport (Non-ECT) packets.
+.TP
 .I CONTROL
 The following keywords allow to control how the tree of qdisc, classes,
 filters and actions is further traversed after this action.

@@ -115,7 +126,7 @@ tc filter add dev eth5 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-Finally, swap the destination and source mac addresses in the header:
+To swap the destination and source mac addresses in the Ethernet header:
 
 .RS
 .EX

@@ -126,13 +137,22 @@ tc filter add dev eth3 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-However, trying to
-.B set
-and
-.B swap
-in a single
-.B skbmod
-command will cause undefined behavior.
+Finally, to mark the CE codepoint in the IP header for ECN Capable Transport (ECT) packets:
+
+.RS
+.EX
+tc filter add dev eth0 parent 1: protocol ip prio 10 \\
+	u32 match ip protocol 1 0xff flowid 1:2 \\
+	action skbmod \\
+	ecn
+.EE
+.RE
+
+Only one of
+.BR set ", " swap " and " ecn
+shall be used in a single command.
+Trying to use more than one of them in a single command is considered undefined behavior; pipe
+multiple commands together instead.
 
 .SH SEE ALSO
 .BR tc (8),

@@ -28,7 +28,7 @@
 static void skbmod_explain(void)
 {
 	fprintf(stderr,
-		"Usage:... skbmod { set <SETTABLE> | swap <SWAPPABLE> } [CONTROL] [index INDEX]\n"
+		"Usage:... skbmod { set <SETTABLE> | swap <SWAPPABLE> | ecn } [CONTROL] [index INDEX]\n"
 		"where SETTABLE is: [dmac DMAC] [smac SMAC] [etype ETYPE]\n"
 		"where SWAPPABLE is: \"mac\" to swap mac addresses\n"
 		"\tDMAC := 6 byte Destination MAC address\n"

@@ -111,6 +111,9 @@ static int parse_skbmod(struct action_util *a, int *argc_p, char ***argv_p,
 			p.flags |= SKBMOD_F_SMAC;
 			fprintf(stderr, "src MAC address <%s>\n", saddr);
 			ok += 1;
+		} else if (matches(*argv, "ecn") == 0) {
+			p.flags |= SKBMOD_F_ECN;
+			ok += 1;
 		} else if (matches(*argv, "help") == 0) {
 			skbmod_usage();
 		} else {

@@ -211,6 +214,9 @@ static int print_skbmod(struct action_util *au, FILE *f, struct rtattr *arg)
 	if (p->flags & SKBMOD_F_SWAPMAC)
 		fprintf(f, "swap mac ");
 
+	if (p->flags & SKBMOD_F_ECN)
+		fprintf(f, "ecn ");
+
 	fprintf(f, "\n\t index %u ref %d bind %d", p->index, p->refcnt,
 		p->bindcnt);
 	if (show_stats) {

@@ -5,12 +5,13 @@ skbmod - user-friendly packet editor action
 .SH SYNOPSIS
 .in +8
 .ti -8
-.BR tc " ... " "action skbmod " "{ [ " "set "
-.IR SETTABLE " ] [ "
+.BR tc " ... " "action skbmod " "{ " "set "
+.IR SETTABLE " | "
 .BI swap " SWAPPABLE"
-.RI " ] [ " CONTROL " ] [ "
+.RB " | " ecn
+.RI "} [ " CONTROL " ] [ "
 .BI index " INDEX "
-] }
+]
 
 .ti -8
 .IR SETTABLE " := "

@@ -25,6 +26,7 @@ skbmod - user-friendly packet editor action
 .IR SWAPPABLE " := "
 .B mac
 .ti -8
+
 .IR CONTROL " := {"
 .BR reclassify " | " pipe " | " drop " | " shot " | " continue " | " pass " }"
 .SH DESCRIPTION

@@ -36,6 +38,12 @@ action. Instead of having to manually edit 8-, 16-, or 32-bit chunks of an
 ethernet header,
 .B skbmod
 allows complete substitution of supported elements.
+Action must be one of
+.BR set ", " swap " and " ecn "."
+.BR set " and " swap
+only affect Ethernet packets, while
+.B ecn
+only affects IP packets.
 .SH OPTIONS
 .TP
 .BI dmac " DMAC"

@@ -48,10 +56,11 @@ Change the source mac to the specified address.
 Change the ethertype to the specified value.
 .TP
 .BI mac
-Used to swap mac addresses. The
-.B swap mac
-directive is performed
-after any outstanding D/SMAC changes.
+Used to swap mac addresses.
+.TP
+.B ecn
+Used to mark ECN Capable Transport (ECT) IP packets as Congestion Encountered (CE).
+Does not affect Non ECN-Capable Transport (Non-ECT) packets.
 .TP
 .I CONTROL
 The following keywords allow to control how the tree of qdisc, classes,

@@ -117,7 +126,7 @@ tc filter add dev eth5 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-Finally, swap the destination and source mac addresses in the header:
+To swap the destination and source mac addresses in the Ethernet header:
 
 .RS
 .EX

@@ -128,9 +137,22 @@ tc filter add dev eth3 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-As mentioned above, the swap action will occur after any
-.B " smac/dmac "
-substitutions are executed, if they are present.
+Finally, to mark the CE codepoint in the IP header for ECN Capable Transport (ECT) packets:
+
+.RS
+.EX
+tc filter add dev eth0 parent 1: protocol ip prio 10 \\
+	u32 match ip protocol 1 0xff flowid 1:2 \\
+	action skbmod \\
+	ecn
+.EE
+.RE
+
+Only one of
+.BR set ", " swap " and " ecn
+shall be used in a single command.
+Trying to use more than one of them in a single command is considered undefined behavior; pipe
+multiple commands together instead.
 
 .SH SEE ALSO
 .BR tc (8),

@@ -28,10 +28,9 @@
 static void skbmod_explain(void)
 {
 	fprintf(stderr,
-		"Usage:... skbmod {[set <SETTABLE>] [swap <SWAPABLE>]} [CONTROL] [index INDEX]\n"
+		"Usage:... skbmod { set <SETTABLE> | swap <SWAPPABLE> | ecn } [CONTROL] [index INDEX]\n"
 		"where SETTABLE is: [dmac DMAC] [smac SMAC] [etype ETYPE]\n"
-		"where SWAPABLE is: \"mac\" to swap mac addresses\n"
-		"note: \"swap mac\" is done after any outstanding D/SMAC change\n"
+		"where SWAPPABLE is: \"mac\" to swap mac addresses\n"
 		"\tDMAC := 6 byte Destination MAC address\n"
 		"\tSMAC := optional 6 byte Source MAC address\n"
 		"\tETYPE := optional 16 bit ethertype\n"

@@ -112,6 +111,9 @@ static int parse_skbmod(struct action_util *a, int *argc_p, char ***argv_p,
 			p.flags |= SKBMOD_F_SMAC;
 			fprintf(stderr, "src MAC address <%s>\n", saddr);
 			ok += 1;
+		} else if (matches(*argv, "ecn") == 0) {
+			p.flags |= SKBMOD_F_ECN;
+			ok += 1;
 		} else if (matches(*argv, "help") == 0) {
 			skbmod_usage();
 		} else {

@@ -212,6 +214,9 @@ static int print_skbmod(struct action_util *au, FILE *f, struct rtattr *arg)
 	if (p->flags & SKBMOD_F_SWAPMAC)
 		fprintf(f, "swap mac ");
 
+	if (p->flags & SKBMOD_F_ECN)
+		fprintf(f, "ecn ");
+
 	fprintf(f, "\n\t index %u ref %d bind %d", p->index, p->refcnt,
 		p->bindcnt);
 	if (show_stats) {

@@ -586,6 +586,18 @@ enum {
 
 #define TCA_ATM_MAX	(__TCA_ATM_MAX - 1)
 
+/* INGRESS section */
+
+enum {
+	TCA_INGRESS_UNSPEC,
+	TCA_INGRESS_FLAGS,
+#define	TC_INGRESS_CLSACT	   _BITUL(0)	/* enable clsact egress mini-Qdisc */
+#define	TC_INGRESS_SUPPORTED_FLAGS TC_INGRESS_CLSACT
+	__TCA_INGRESS_MAX,
+};
+
+#define	TCA_INGRESS_MAX	(__TCA_INGRESS_MAX - 1)
+
 /* Network emulator */
 
 enum {

@@ -17,21 +17,45 @@
 
 static void explain(void)
 {
-	fprintf(stderr, "Usage: ... ingress\n");
+	fprintf(stderr,
+		"Usage: [ add | replace | link | delete ] ... ingress\n"
+		"       change ... ingress [ clsact-on | clsact-off ]\n"
+		" clsact-on\tenable clsact egress mini-Qdisc\n"
+		" clsact-off\tdelete clsact egress mini-Qdisc\n");
 }
 
 static int ingress_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 			     struct nlmsghdr *n, const char *dev)
 {
+	struct nla_bitfield32 flags = {
+		.selector = TC_INGRESS_SUPPORTED_FLAGS,
+	};
+	bool change = false;
+	struct rtattr *tail;
+
 	while (argc > 0) {
 		if (strcmp(*argv, "handle") == 0) {
 			NEXT_ARG();
-			argc--; argv++;
+		} else if (strcmp(*argv, "clsact-on") == 0) {
+			flags.value |= TC_INGRESS_CLSACT;
+			change = true;
+		} else if (strcmp(*argv, "clsact-off") == 0) {
+			flags.value &= ~TC_INGRESS_CLSACT;
+			change = true;
 		} else {
 			fprintf(stderr, "What is \"%s\"?\n", *argv);
 			explain();
 			return -1;
 		}
+
+		argc--;
+		argv++;
+	}
+
+	if (change) {
+		tail = addattr_nest(n, 1024, TCA_OPTIONS);
+		addattr_l(n, 1024, TCA_INGRESS_FLAGS, &flags, sizeof(flags));
+		addattr_nest_end(n, tail);
 	}
 
 	return 0;

@@ -40,7 +64,25 @@ static int ingress_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 static int ingress_print_opt(struct qdisc_util *qu, FILE *f,
 			     struct rtattr *opt)
 {
+	struct rtattr *tb[TCA_INGRESS_MAX + 1];
+	struct nla_bitfield32 *flags;
+
 	print_string(PRINT_FP, NULL, "---------------- ", NULL);
+
+	if (!opt)
+		return 0;
+
+	parse_rtattr_nested(tb, TCA_INGRESS_MAX, opt);
+
+	if (!tb[TCA_INGRESS_FLAGS])
+		return -1;
+	if (RTA_PAYLOAD(tb[TCA_INGRESS_FLAGS]) < sizeof(*flags))
+		return -1;
+
+	flags = RTA_DATA(tb[TCA_INGRESS_FLAGS]);
+	if (flags->value & TC_INGRESS_CLSACT)
+		print_string(PRINT_FP, NULL, "clsact", NULL);
+
 	return 0;
 }
 

@@ -8,7 +8,8 @@ skbmod - user-friendly packet editor action
 .BR tc " ... " "action skbmod " "{ " "set "
 .IR SETTABLE " | "
 .BI swap " SWAPPABLE"
-.RI " } [ " CONTROL " ] [ "
+.RB " | " ecn
+.RI "} [ " CONTROL " ] [ "
 .BI index " INDEX "
 ]
 

@@ -37,6 +38,12 @@ action. Instead of having to manually edit 8-, 16-, or 32-bit chunks of an
 ethernet header,
 .B skbmod
 allows complete substitution of supported elements.
+Action must be one of
+.BR set ", " swap " and " ecn "."
+.BR set " and " swap
+only affect Ethernet packets, while
+.B ecn
+only affects IP packets.
 .SH OPTIONS
 .TP
 .BI dmac " DMAC"

@@ -51,6 +58,10 @@ Change the ethertype to the specified value.
 .BI mac
 Used to swap mac addresses.
 .TP
+.B ecn
+Used to mark ECN Capable Transport (ECT) IP packets as Congestion Encountered (CE).
+Does not affect Non ECN-Capable Transport (Non-ECT) packets.
+.TP
 .I CONTROL
 The following keywords allow to control how the tree of qdisc, classes,
 filters and actions is further traversed after this action.

@@ -115,7 +126,7 @@ tc filter add dev eth5 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-Finally, swap the destination and source mac addresses in the header:
+To swap the destination and source mac addresses in the Ethernet header:
 
 .RS
 .EX

@@ -126,13 +137,22 @@ tc filter add dev eth3 parent 1: protocol ip prio 10 \\
 .EE
 .RE
 
-However, trying to
-.B set
-and
-.B swap
-in a single
-.B skbmod
-command will cause undefined behavior.
+Finally, to mark the CE codepoint in the IP header for ECN Capable Transport (ECT) packets:
+
+.RS
+.EX
+tc filter add dev eth0 parent 1: protocol ip prio 10 \\
+	u32 match ip protocol 1 0xff flowid 1:2 \\
+	action skbmod \\
+	ecn
+.EE
+.RE
+
+Only one of
+.BR set ", " swap " and " ecn
+shall be used in a single command.
+Trying to use more than one of them in a single command is considered undefined behavior; pipe
+multiple commands together instead.
 
 .SH SEE ALSO
 .BR tc (8),

@@ -28,7 +28,7 @@
 static void skbmod_explain(void)
 {
 	fprintf(stderr,
-		"Usage:... skbmod { set <SETTABLE> | swap <SWAPPABLE> } [CONTROL] [index INDEX]\n"
+		"Usage:... skbmod { set <SETTABLE> | swap <SWAPPABLE> | ecn } [CONTROL] [index INDEX]\n"
 		"where SETTABLE is: [dmac DMAC] [smac SMAC] [etype ETYPE]\n"
 		"where SWAPPABLE is: \"mac\" to swap mac addresses\n"
 		"\tDMAC := 6 byte Destination MAC address\n"

@@ -111,6 +111,9 @@ static int parse_skbmod(struct action_util *a, int *argc_p, char ***argv_p,
 			p.flags |= SKBMOD_F_SMAC;
 			fprintf(stderr, "src MAC address <%s>\n", saddr);
 			ok += 1;
+		} else if (matches(*argv, "ecn") == 0) {
+			p.flags |= SKBMOD_F_ECN;
+			ok += 1;
 		} else if (matches(*argv, "help") == 0) {
 			skbmod_usage();
 		} else {

@@ -211,6 +214,9 @@ static int print_skbmod(struct action_util *au, FILE *f, struct rtattr *arg)
 	if (p->flags & SKBMOD_F_SWAPMAC)
 		fprintf(f, "swap mac ");
 
+	if (p->flags & SKBMOD_F_ECN)
+		fprintf(f, "ecn ");
+
 	fprintf(f, "\n\t index %u ref %d bind %d", p->index, p->refcnt,
 		p->bindcnt);
 	if (show_stats) {